By Dan Frommer.From the archives.Wednesday, September 14, 2011 at 2:30 pm.

Will Android ever beat Google’s search market share?

I posted yesterday about how Google’s search share seems “stuck” at 65%. At first blush, 65% seems low, considering that the word “Google” is synonymous with search. But search is fragmented, and rival portals with huge audiences or big budgets — Yahoo and Microsoft — can still apparently eat up a lot of share.

My next thought was: If 65% is considered Google-search-level dominance of a market, will Google Android ever reach that level? Below is a chart of Google’s search share (the gray line near the top) and the top 4 smartphone platforms. All the data is U.S.-only, from comScore, though the mobile platform share represents a 3-month average.

On paper, it certainly seems possible for Android to reach Google’s search share: Over the past year, Android has risen to 42% of the market from 17%. If Google maintains the same trajectory for another year, it could reach 67%. But it’s more complicated than that.

The biggest variable is what Apple’s share will look like in a year. It has grown modestly over the past year to 27% from 24%. But let’s see what happens with the iPhone 5. If it becomes available at all four major carriers — with Sprint and T-Mobile its newest distributors — Apple stands to gain share. And because many would-be iPhone buyers are currently buying Android phones, Apple’s growth could come at Google’s expense. It wouldn’t be surprising if Apple’s share was at 35% or greater in a year.

Then, to reach 65% of the market, Google would have to claim everything that Apple doesn’t have, and that doesn’t seem likely. Even though mobile is becoming a 2-horse race, there are still several companies vying for no. 3, and that’s not likely to stop.

RIM has crashed to 22% of the market, from 39% a year ago. But it will maintain some of the market for a while, especially among its business customers. Let’s say about 10% in a year, unless its new QNX platform is a miracle.

Microsoft — despite the critically acclaimed launch of Windows Phone 7 — is still in decline. Its partnership with Nokia will be worth watching, but isn’t worth betting on. (Microsoft is now around 6%.)

The “other” OSes (Palm, Symbian) have fallen to 4% share from 8% a year ago, and will eventually go to 0. But keep an eye on new entrants, such as Facebook or even Amazon.

So let’s assume that RIM, Microsoft, and “other” will be around 15% of the market in a year, down from 30% now. If Apple takes up another 35%, that only leaves about 50% for Google — not actually much higher than it is today. (And nowhere near the level that Microsoft Windows still has in the PC business.)

The battle to watch, then, remains Google vs. Apple. So far, Google hasn’t given iPhone users a good reason to buy Android phones instead of iPhones. Will that ever happen? Or could the iPhone — with wider distribution across all major U.S. carriers, and still a superior product — even take the lead?

(Semi-related: For Google’s core search business, Android and iOS success are both good for Google, as it’s still the default search engine on iPhones and most Android devices. That’s not likely to change unless Apple ever creates its own search engine.)